I see where you're going with taking the toy into different environments to produce varied challenges. Controlling multiple vehicles at once could be interestin

I see where you're going with taking the toy into different environments to produce varied challenges. Controlling multiple vehicles at once could be interesting- I'm reminded of tool-assisted speedruns in which a single set of gamepad inputs are used to complete different games simultaneously. You could create obstacle courses where the same program will help all the robots get out. From the perspective of learning about abstraction and code reuse, I think having a single function definition that can only be four instructions long is very limiting. If you had more (even just a second one) you'd have many more ways of combining them together- they could be chained, they could call one another, etc- and thus more ways to try breaking down problems. Breaking tasks down into smaller subtasks is, in my opinion, one of the most fundamental concepts in programming, and your toy can teach this idea. From a totally different angle, have you thought about adding a crayon/marker mount to the car so that kids can lay out a big piece of paper and then have a visual record of their trial-and-error progress? Thinking about the toy as a sort of creative tool, if the kids had some ability to turn the overall program into a repetitive loop rather than just a sequence you could do some neat spyrograph style stuff. Maybe add a toggle switch to enable that?